Orient Lake opens widely onto the plain, inside a major migratory corridor. Thousands of birds frequent its waters, especially in late summer and fall. The vast mudflats uncovered during these periods attract more than 35 species of shorebirds, thousands of ducks, and a few hundred geese. The fish trapped in the water pockets constitute easy prey for the gray heron, the great egret, and especially the black stork, for which Orient Lake represents the main postnuptial concentration site in France. Thousands of common cranes, symbols of the reservoir lake, also pass there during migrations and winter.